104 



Museum collection. They are of a bright golden colour, and are 

 extreme females strongly dusted with yellow scales. 



I trust, Gentlemen, that I have interested you in Zygana achillece, 

 that I have made you in some small degree realise and understand 

 (have called to mind perhaps some parallel case in your own experi- 

 ence) the exquisite pleasure I felt when studying Zygcena acliillere 

 in those scented vistas which stretch up among the larch trees, whilst 

 the warmth of barred sunshine, filtered through the velvet canopy 

 overhead, made a delightful spot still more lovely and enchanting, 

 whilst the green banks swept down in emerald undulation to the 

 rapid Dora, whose distant hum murmurs even now perhaps on the 

 ear in the stillness of the scent-laden air, and where the naturalist 

 can pursue his studies and dive into the recesses of Nature in a 

 land which has not yet been captured by the few, who close to the 

 many some of Nature's most glorious heirlooms and gifts to all her 

 children, where that curse of the naturalist has not yet been 

 formulated — " Trespassers will be prosecuted." 



Zygaena transalpina, Esp., and its varieties. 



By J. ^V. TuTT, F.E.S. Read November 22nd, 1894. 



Probably the most beautiful of the six-spotted Burnet moths is 

 ZygcEua transalpina. In the early morning, when the sun has just 

 worked his way upwards sufficiently to send his oblique rays glancing 

 through the tops of the larch trees, and to form fine pencils of light 

 on the flowers and grasses in the hollows, is the time to see Z. 

 transalpina. At that time the pupa pushes its way out of its 

 yellow, boat-shaped silken cocoon, and dehiscing in genuine Burnet 

 fashion, allows the strange, soft imago to creep out. The latter 

 rapidly walks up the stem of larch or juniper, hazel or barberry, on 

 which the cocoon has been spun, and hangs down its limp wings ; 

 these rapidly expand, and in a few brief minutes become an epitome 

 of brightness and brilliancy. 



Few Burnet moths attain such a perfection of rich purple, or such 

 a marvellous depth of beautiful green. This differentiation of the 

 ground colour is largely sexual, the gentlemen being clad usually in 

 the purple, the ladies in the dress of verdant hue. But fluctuating 

 and changeful are these colours, and green becomes purple and 

 purple green, as the rays of light fall at different angles upon the 

 scales. You scarcely believe it ? Look at the insects, as with their 

 heads straight towards you, and males and females alike are of the 

 richest metallic purple. Now turn them round, with their heads 

 from you, and they become changed to a metallic green. But as 

 you vary the angle you soon discover that normally some are purple, 

 others green, and that largely this is a matter of sex. 



